In the trailer above for the movie My Urban Playground, there's a quick discussion of the fact that Colossal Order and Paradox Interactive's wildly successfulCities: Skylines has been used for real-world urban planning -- of a new transportation system in Stockholm, Sweden.

It's part of a larger discussion of how games can interact with real cities, which is the subject of the documentary.

The documentary will have a "sneak peek" this weekend at SXSW in Austin, Texas, which Paradox Interactive is co-sponsoring with film agency Luckyday.

"It shouldn’t come as a surprise that among our millions of players, we have plenty of architects, urban planners, public officials, and many more people who have found parallels between the game and their professional lives," said Paradox COO Susana Meza Graham in a statement.